Remark 3.2 We recall that the equation (REF ) can be derived from another triplet without the tetrahedron property. As it was discussed in [1]}, [2]} the equation (REF ) can thought as \(A\)  equation of the following triplet (we are already on the lattice)
\(A= v_{n,m,p}v_{n+1,m+1,p}+v_{n+1,m,p}v_{n,m+1,p},  \\B= v_{n,m,p}v_{n,m+1,p+1}+v_{n,m+1,p}v_{n,m,p+1},  \\C= v_{n,m,p}v_{n+1,m,p+1}+v_{n+1,m,p}v_{n,m,p+1}, \) 
